im not sure

hi. all
i have a wired starter kit. and have managed to set up the wifi bridge with the thermostat
im stuck on this bit. when i removed my old thermostat it had 2 wires. i tested these with a meter and it was 240v. so mains? if i join these to wires together the boiler fires up. so it must need a relay in the tado so my question is. where in the tado do i put these 2 wires. ? thanks for your time. cheers kev